I suspect I have a failing bearing. Maybe the clamping action of braking firms it up.

Its being centred instead of being free to wobble.

I wonder if OP used the chassis no to get the new disc?.

A Mk4 Golf is going to be an old car now. During its life its almost certainly had a number of components replaced and if any have been off "similar" Golfs and not from a 130TDi of the correct year it cold result in clearance issues.

Parts change during a models lifetime, is the OP 100% certain he has the correct ones.

I would hope that VW ensures that part changes are checked for interchangeability.

When I worked for a maker of engine components any design change proposed was run through reviews to ensure all versions of a specific part number were interchangeable with earlier ones: if not, a new part number would be created and service data amended to show the serial number from which the change took effect.

For your (and others) own safety I'd ask a local independent garage or VW specialist to have a look. Something sounds very wrong.

Thanks for the messages. I was fairly certain I had the right part using the registration plate but as you say this does assume that over the last 17ish years the callipers haven’t been replaced with something subtly different. However from a visual comparison they also looked the same. The spacer thought is a good point, there wasn’t one that I noticed. It could have rusted to the inside of the brake disc but I think I would have noticed. However, the use of a spacer would be a better solution than pushing the calliper back as this would avoid shortening the amount of calliper bracket bolt holding the bracket together. It doesn’t need to move forward a lot though. Are these spacers standard items or is it a matter of using something else to do the job? Depending on the size presumably I may also have to change the wheel nuts as they may have to be slightly longer? Thanks Matt

Unwise to make DIY modifications to your braking system. Get new parts that fit properly.

Chassis number should get you the correct parts, only time I have ever found problems with that, is on a changeover where the maker has upgraded/changed a part and they were not always catalogued as has been said earlier.

This would seem to imply you've never had a Renault 5 (and by extension, any other Renault, or maybe any other French car?), which would be surprising.

Main dealer, given chassis number, could not tell me which of several different brake assemblies, or even which make,(Bendix, Girling, or something else I've forgotten) were likely to have been fitted.

Could have been a ploy to get my car in the workshop (in which case it failed) but I've heard it from other reliable sources.

Its a FRENCH thing, apparently..

In some cases it was easier to take the part in with you to get the right part, but sometimes even that didn`t work

Many many years ago in Switzerland, a local garage came in to us asking for a starter motor for a mini. They had the old unit with them., and as it was an exchange item, I matched it to the new one, Identical part number, so ok.

Few months later, came back with teeth all worn out... Sent off for warranty, Claim denied as the

owner had fitted an engine from a scrappy, and fitted their own starter motor, except that the engine fitted was an old one and didn't match.

If someone comes in with the wrong part then it can be fun!

You might have to helicoil it (or equivalent) or maybe it would be easier and more satisfactory just to replace the caliper.

Hi Thanks for the thoughts. I’ve taken another look and I have realised that one side has a nut on the bolt holding the calliper to the bracket and the other side does not. It is the extra length that this nut is adding that is resulting in the nut just rubbing against the disc. Everything else (from a dimension perspective) appears to be exactly the same so my next step is to remove the bolts and work out why one side would require a nut and the other wouldn’t. Could it be that the threads in the calliper or bracket have been stripped and they resorted to a nut and bolt? Guess I’ll find out when I take them both apart again. Thanks Matt

It might mean getting a new hub assy if the thread is stripped ?

This would seem to imply you've never had a Renault 5 (and by extension, any other Renault, or maybe any other French car?), which would be surprising.

Not sure why it`s surprising, and no, never had any of those due to so many problems with them apart from the fact I didn`t like any of them.

Because, from the evident breadth of your experience, I assumed you'd been a general mechanic and would have worked on them, if not "had", as in owned, one. My mistake

DP, sorry

Edited by edlithgow on 24/05/2021 at 01:45

Could you tap it?

Or have it tapped, or helicoiled, but that might cost more than replacement.

Edited by edlithgow on 24/05/2021 at 02:06

I have finally been able to revisit and take the calliper apart, the issue is definitely the bolt for the calliper mounting bracket, the threads in the ‘knuckle’ (not sure if this is the right term) were stripped and the treads on the bolt themselves are a bit ropey. Nothing I can do about the stripped threads without replacing the knuckle which I don’t fancy so my plan is to replaced the bolt (as there are still some threads remaining) and then use a nut as has been done previously, just a smaller one so it doesn’t rub on the disc. However, I am struggling to work out the dimensions of the bolt to be able to buy a replacement. I would appreciate any thoughts on how to go about replacing. Thanks Matt

Personally I think it would be better to get hold of a secondhand hub assembly and fit that. You're dealing with one of the most safety-critical components on the car.

New ones if the car is correct (no Date given) carriers around £40 plus fitting- possibly second hand about £40 complete, I would have thought, without fitting from scrap yard (just a thought) would be better than risking a rethread or bolt nut combi, as mentioned above